This allows for iterating over all the flash object (in handlebars at least), and using the keys to set the class, rather than checking if we have a flash.error, flash.info, etc…
{{#each flash}}
{{#each this}}
<div class="alert alert-{{@key}}">
<button type="button" class="close" data-dismiss="alert">&times;</button>
{{this}}
</div>
{{/each}}
{{/each}}